function getStyle(obj,attr){
	if(obj.currentStyle){
		return obj.currentStyle;	
	}else{
		return getComputedStyle(obj,false)[attr];		
	};
};
function startMove(obj,json,fn){
	clearInterval(obj.timer);
	obj.timer=setInterval(function(){
		var flag=true; 	//这一次运动就结束了---所有的值都到达了
		for(var attr in json){
			var iCur=0;
			if(attr=='opacity'){
				iCur=parseInt(parseFloat(getStyle(obj,attr)*100));
			}else{
				iCur=parseInt(getStyle(obj,attr))	
			};
			var speed=(json[attr]-iCur)/8;
			speed=speed>0?Math.ceil(speed):Math.floor(speed);
			if(iCur!=json[attr]){
				flag=false;	
			}
			obj.style[attr]=iCur+speed+'px';
			if(attr=='opacity'){
				obj.style.opacity=(iCur+speed)/100;
				obj.style.filter='alpha(opacity:'+(iCur+speed)+')';	
			};
					
		};
		if(flag){
			clearInterval(obj.timer);
			if(fn){
				fn();	
			}	
		}
	},30)	
}
